The general interface and the programs for the multi-physical analysis of the traction transformer were designed, which combined the advantages of the interface design of VB with the secondary development of ANSYS. The research staff needs only to input the structure parameters and electrical parameters, and all the parameters were automatically matching with the ANSYS APDL programs. The finite element model of the traction transformer was established through VB calling ANSYS, and calling the different physical programs and post-processing programs. The multi-physical analysis and calculation were completed by avoiding fussy program input and shortening the design cycle of new products, which indicates that the analytical interface will be valuable in engineering application.